The present invention relates to a beaded black, a process for its production and its use.
In the processing of industrial carbon blacks, pelletized products, commonly known as beaded black, are preferably used. Two different methods are used for pelletizing carbon blacks on an industrial scale: wet pelletizing in a pelletizing machine with subsequent drying, and dry pelletizing in a pelletizing drum. The two methods have markedly different process parameters, which are closely linked to the physical processes involved in agglomeration in each case and to the resulting bead properties (Ullmanns Encyklopädie der technischen Chemie, 4th Edition, Volume 14, page 639–640 (1977)).
A beaded black is known from EP 0 924 268 which contains at least one natural and/or synthetic wax and which is obtained by pelletizing a powdered starting black, whereby the content of waxes in the beaded black is 1 to less than 10 wt. %, relative to the total weight of beaded black, and the hardness of the individual beads in the beaded black is greater than 0.15 N.
The disadvantage of the known beaded blacks is their poor dispersibility at the specified bead hardness.
It is therefore an object of the present invention to produce a beaded black having improved dispersibility, abrasion resistance, flow behaviour and transport stability.